ASSOCIATION BETWEEN IRON AND THYROID STATUS IN PREGNANT WOMEN

Purpose: Pregnancy is often complicated by iron deficiency, affecting negatively thyroid gland physiology. The aim of our study is to investigate parameters of iron and thyroid status during I, II and III trimester of pregnancy in order to establish potential correlations in their dynamics. Materials and methods: The study involved 61 pregnant women and 43 controls. Their iron and thyroid status was determined by measuring hemoglobin (Hb), serum ferritin (SF), serum transferrin receptor (sTfR), thyroxine (FT4) and thyroid-stimulating hormone (TSH). Results: Significant differences between pregnant women and the control group were found, indicating an iron deficiency risk: sTfR level was higher, while Hb, ferritin and FT4 levels were lower in pregnant women. Thyroxine correlated positively with Hb (p= 0.016) and ferritin (p = 0.003) in pregnant women. In the I trimester, there was a negative association between sTfR and FT4 (p = 0.013), and in the III trimester, there was a positive association between sTfR and TSH (p < 0.0001). Conclusions: sTfR represented the relationship between iron and thyroid status in the I and III trimester. Iron deficiency was expressed in the III trimester with a positive association between sTfR and TSH. The increased maternal iron requirement (sTfR) correlated with increased TSH secretion induced by decreased thyroxine.